The site design looks fine and is even across the latest versions of Firefox, Netscape, IE and Opera. I only examined your index page because there are problems with it that are also present on other pages.
First off, the page was very slow to load, well over a minute in Netscape on an ADSL connection! The others browsers also had trouble, displaying nothing but whiteness for well over 15 seconds. The reason for the delay is a large number of errors. According to the
W3C Validator some of your code is not utf-8 and as a result aborted the check. This error will delay the browsers too, while they try to work out what they're reading.
There are actually over 100 errors in the code including missing ALT tags (9 important ones) and loads of invalid VALIGNs amonst others.
If I were you I would convert the code to XHTML, clean it up and complete the job with informative ALT tags. Cleaning up the code shouldn't be too tricky but the site design warrants it.
Good luck.
PS. I've edited some comments out because I made an error!